In employment law, if you don't have an employment contract specifically stating that you can only be terminated for cause, you are an 'at will' employee. I know you didn't mentioned termination, but this is important to understand because it establishes your employment status. If you are an "at will" employee, that severely limits your options or protections. Most people are "at will" employees, so it is very likely that you are too. If you have a contract like that, the answer is simple...you sue for breach of contract, because part of having a contract for your job is being able to work that job in peace.
However, without a contract, how does the law look at harassment? The Supreme Court stated, when it defined "hostile work environment" that our employment laws are not meant to be a civility code. Instead, it is only intended to stop illegal forms of harassment, specifically made illegal by statute. Among those would be harassment directed at your race, religion, gender, age, disability, recent FMLA use, worker's compensation use, OSHA complaints or wage and hour complaints to the Department of Labor. Generalized harassment, meaning the unprofessional behavior of someone which isn't directed at any of those factors, is not illegal in employment law. If the harassment is based on one of these factors (or you believe it may be), then you file an EEOC complaint for the race, religion, gender, age or disability discrimination, a Department of Labor complaint for the FMLA or wage and hour discrimination, or an OSHA complaint for the OSHA discrimination.
If you can't point to one of those factors as the basis for the treatment, you can next look at the employer's handbook or written policies to see if anything in there creates a right to work in a harassment free workplace. If so, you can technically sue the employer for breach of that implied contract. This gets tricky because it really is only useful to do if you are fired or after you quit. Unlike a complaint to the EEOC, DOL or OSHA, suing a company for breach of contract doesn't come with protection against retaliation.
Finally, there is the option to complain to HR or some boss over the manager, explaining that continued treatment like this will force you to have to quit. This could get you terminated (and you'd get unemployment), but it is intended to set up the right to resign and still get unemployment because you gave the employer the chance to resolve the issue and they did not.